1. Field of the Invention
This invention relates to a handle assembly for use with a saw blade to form a foldable saw, more particularly to a handle assembly which facilitates mounting and detaching of a saw blade and which permits folding and unfolding of the saw blade on the handle assembly.
2. Description of the Related Art
U.S. Pat. No. 5,553,386 discloses a foldable saw which includes an elongated handle member, a saw blade, and a locking unit. The handle member has opposite side walls and a top wall which bridges the side walls. The side walls confine a longitudinal slit therebetween. The saw blade is formed as an elongated flat plate with a teethed edge. The saw blade has a tip and a rounded end portion which is opposite to the tip and which is mounted pivotally on the handle member such that the saw blade is pivotable between a folded position, wherein the saw blade is concealed within the slit of the handle member, and an unfolded position, wherein the saw blade is extended from the handle member. The locking unit is mounted on the handle member and is operable so as to engage releasably the rounded end portion of the saw blade to lock the saw blade in a selected one of the folded and unfolded positions. The saw blade has an indented section located between the rounded end portion and the teethed edge. The top wall of the handle member is formed with a through hole which extends to the slit and which is aligned with the indented section of the saw blade when the saw blade is in the folded position. The through hole has a release spring disposed therein. The through hole further has an internally threaded upper section which engages an externally threaded plug that abuts against one end of the release spring. The release spring is compressed by the saw blade when the saw blade is locked by the locking unit in the folded position. The release spring expands to cause the tip of the saw blade to project out of the slit of the handle member when the locking unit is operated to unlock the saw blade from the folded position. The rounded end portion of the saw blade is sized so as to abut against the release spring when the saw blade is in the unfolded position.
The saw blade is mounted pivotally on the handle member by means of a bolt that extends through a pivot hole in the saw blade and through the handle member to engage a nut. When the saw blade is to be removed from the handle member for replacement with a new one, the bolt must be unthreaded from the nut with the use of a tool so as to disengage the same from the saw blade and the handle member. After a new saw blade is inserted into the handle member, the bolt must be extended through the saw blade and the handle member for threadedly engaging the nut. Although the foldable saw permits removal of the saw blade for replacement, threading and unthreading operations of the bolt are necessary. Thus, the replacement operation of the saw blade of the conventional saw is not convenient to conduct.